1. Field of the Invention
This invention relates to an automotive display system and a display method.
2. Background Art
Automotive display devices include a group of display devices called HUDs (Head-Up Displays). In such display devices, an image presented by an image formation device such as an LCD, a CRT, etc., is reflected by a semi-transmissive reflector such as a half mirror via an optical system and provided to an observer operating a vehicle. The semi-transmissive reflector, called a combiner, provides an image superimposed on external environment information to the observer by reflecting the image from the image formation device and transmitting the external environment information. As a result, the observer can simultaneously visually identify the external environment information and the image information from the image formation device.
There is a strong desire for such a display device to project by substantially superimposing the presented image information on the external environment information forming the background, and to project by disposing the presented image information at, for example, a position corresponding to the spatial position of the external environment information. In particular, attempts are being made to present vehicle route information better suited to the external environment information of the background to use in car navigation for automobiles.
For example, JP-A 2006-284458 discusses technology to dynamically modify the display mode of an arrow according to the traveling state of a vehicle and/or the traffic conditions around the vehicle when displaying a moving image of the arrow to indicate the direction in which the vehicle should proceed. In this technology, the degree of safety is determined according to the traveling state of the vehicle and/or the traffic conditions around the vehicle, and the display mode of the arrow such as the display position, the color, the clarity, the operation, the configuration, and the size is modified.
JP-A 2006-17626, for example, discusses technology to present an image of an arrow and the like while changing the size of the image according to the passage of time during a movement of a moving object such that the image is overlaid on the landscape seen frontward of the windshield of the moving object.
However, in such conventional HUDs, there is no consideration given to shifting of the display in the case where, for example, the attitude of the vehicle (e.g., the slant rearward and frontward and/or the slant left and right, etc.) is shifted from the configuration of the road frontward of the vehicle (e.g., the slant uphill and downhill and/or left and right, etc.). Therefore, in the case where the attitude of the vehicle is shifted from the configuration of the road, the arrow, for example, displayed in the HUD is undesirably shifted from the road, and an incongruity results.
In conventional HUDs such as those recited above, the subjective depth position (the perceived depth position) of the presented information observed as a virtual image undesirably matches the virtual image distance. Therefore, no matter the presented information, it is difficult to match the perceived depth position of the presented information to the actual spatial position.